list with named elements m0,
C0, FF, V, GG, W and,
optionally,
JFF, JV, JGG, JW, and
X. The first six are the usual vector and matrices that define
a time-invariant DLM. The remaining elements are used for time-varying
DLM. X, if present, should be a matrix. If JFF is not
NULL, then it must be a matrix of the
same dimension of FF, with the \((i,j)\) element being zero if
FF[i,j] is time-invariant, and a positive integer \(k\)
otherwise. In this case the \((i,j)\) element of FF at time
\(t\) will be X[t,k]. A similar interpretation holds for
JV, JGG, and JW. ... may have additional
components, that are not used by dlm. The named components
may also be passed to the function as individual arguments.